Thanks for setting me straight

Nothing like lecturing a guy, then find out you don't know your head from your hindquarters.

Another thing about the stock tranny cooler...because the trans coils in the radiator are located on the passenger side, they are surrounded by the coldest of the coolant that is in the radiator. The radiator is a cross flow design and the passenger side is the "after cooling" side of the radiator. So the temp on that side of the radiator is much colder than the drivers side.

big_news_1, thanks for that very detailed reply! That realy helped me understand more of exactly WHAT the shudder is. By your definition, it most certainly is NOT an ignition misfire. What it is thou, I'm not sure?

I will try to find out what this COULD be, but I'm not very confident that I will turn up anything as I have never seen this type of tranny problem before. But in the mean time I can only suggest that adding auxillary cooling to the trans is the right thing to do in order to try to keep the temps down.

One thing for you to have checked thou is the flow rate of the stock trans cooler. Gallons Per Minute. To the best of my knowledge GM dealers are the only shops that have a machine that performs this test. If the stock trans cooler is restricted it will significantly reduce the cooling ability and result in overheated trans temps....even with auxillary coolers because the main cooler can't flow enough volume. I'll try to get some specs for you tomorrow on what the flow rates should be.

Also, try very hard to get your hands on a scan tool that reads trans temps and tell us what temp this is happening at. That would be very helpfull.

Hi

I have a laser temperature sensor at work... maybe I will borrow it one day and take some temperature readings. They are not that accurate but will give us a reading of several temperatures.

CHCPMAN

My TC will still work when it is in the 80'*. Before it threw the light I had the "slipping" occuring. Today however the TC did not lock up at all, I was running at about 2500RPM on the highway going 75MPH, which is high for me. It was also about 95* out. This caused my car to run at about 220* for most of the 15 mile trip on the interstate. This is not the first time that this has happened to me, I believe it has happened once or twice before.

I dont know if this is related or not, but when its really cold out in the winter my car will not shift into 4th gear until it is warmed up.

That is most likely normal as the computer will not enable TCC enguagement until the trans fluid reaches a certain temp. I'm not sure what that temp is though. I THINK it'* around 100-120 degrees F.

no, like I dont have 4th gear AT ALL.

usuallyehen pople are having TC problems the TC will work when cold but not hot..............

OK, that is not normal. Any other hints or clues?

Mike you say it won't go at all. Are you sure it is not just delayed to get the temps up? My 00 truck specifically says it will delay shifting points to make itself heat up faster. I'm thinking you mention 75mph as fast for you and am wondering if you are not seeing 4th at 50-55mph.

it doesnt shift into 4th until the temp is around 150*. That means I have to drive at 50-60 until then. I know my TC is bad, I probably need a new tranny too (185,000 miles will do that).